[aap1966]

Reported by NYT, so I can't vouch for accuracy:

In what no doubt seemed like a good idea at the time, Slovak officials decided to test airport security in Slovakia on Saturday by concealing plastic explosives in eight suitcases and waiting to see what happened next.

Here’s what happened next: airport security workers intercepted seven of the suitcases but failed to detect 96 grams of the plastic explosive RDX loaded into one bag, which belonged to a Slovak electrician who lives in Ireland and had no idea his luggage had been tampered with. The man boarded his flight to Dublin, retrieved his bag and went home to his apartment.

The man then unpacked but, The Irish Times reports, “the explosives had been concealed so well that he did not find them.”

Three days later, on Tuesday, it occurred to someone in Slovakia that the fact that one of the explosive-packed bags had gone missing was a problem.
Slovakian airport authorities contacted Dublin to ask for help.

On Tuesday morning, the Irish Army’s bomb squad paid a visit to the apartment of the Slovak electrician in Dublin and secured the explosives.
According to a Canadian Press report, the man was detained for several hours by the Irish police who said they “initially were led to believe the man might be a terrorist.” The man was released after Slovak officials made it clear that they had been responsible for planting the explosives.

On Wednesday morning, The Associated Press reported, Slovakia’s interior ministry issued a statement explaining that “The aim of the training was to keep sniffer dogs in shape and on alert in a real environment.” According to the ministry, the bag that made it past the dog had two bomb components in it. The sniffer dog apparently found one of the components, but the police officer in charge of the test failed to remove the second component because he was busy.